Assessing the knowledge, attitude, and practice of hospital-based pharmacists in reporting adverse drug reactions in Lagos, Nigeria

INTRODUCTION

Adverse drug reactions (ADRs) are defined as any noxious, undesired, or unintended response to a therapeutic agent, which may be expected or unexpected, and may occur at dosages used for the prophylaxis, diagnosis, or treatment of disease, or for modifying physiological function. They do not include therapeutic failures, poisoning, accidental, or intentional overdoses.^[1] Also defined as a “noxious and unwanted response to a medicine” by the European Medicine Agency,^[2] ADRs are a broad term used to describe unwanted and dangerous effects caused by the use of medications. A classification of ADRs as suggested by Thomson and Rawlins in 1981, groups ADRs mainly into Type A and Type B ADR reactions. However, this has been modified to include types C, D, E, and F.^[1] Type A reactions are unusual responses to medications administered at therapeutic doses. They are much more common and less fatal than Type B reactions which are unrelated to the dose and pharmacological action of the medication. Type C reactions occur due to an accumulated dose of a long-term medication; Type D reactions are delayed reactions, which occur long after the medication has been used; Type E reactions occur on withdrawal of a medication; and Type F reactions occur when a medication therapy is ineffective and considered as a failed therapy. ADRs differ from side effects, which are unintended effects, within an expected range of therapy, when a medication is used at normal doses.^[3] ADRs are one of the major causes of morbidity and mortality associated with drug use. ADRs can cause or prolong hospital admissions and are increasingly becoming a growing public health concern with 15% of all patients affected by ADRs and 0.32% of all inpatients experiencing fatal ADRs.^[4] ADRs are also among the top 10 causes of increasing healthcare cost in the United States and Europe.^[5]

The primary tool for reporting ADRs in Nigeria is a structured in-take form known as the “Adverse Drug Reactions Form” (ADR Form). This form is similar to the United Kingdom’s yellow form with a fully completed ADR form, known as the Individual Case Safety Report. Nigeria is in a major crisis of under reporting ADRs.^[5,6] With only 16,500 out of 80,000 ADR forms submitted back to the National Agency for Food and Drug Administration (NAFDAC) after being distributed nationwide for 12 years (2004–2016), this falls short of a World Health Organization’s criterium of 200 reports per million inhabitants per year.^[5,6]

It is estimated that with a growing population of about 213 million people in 2021, about 42,600 reports should be submitted annually.^[7] However, studies have revealed underreporting of ADRs in Nigeria. Opadeyi et al.^[8] revealed poor pharmacovigilance documentation in tertiary hospitals of the South-South zone of Nigeria with the maximum number of ADR reports as 26 in a single year. Another study by Ohaju-Obodo and Iribhogbe^[9] showed low reporting rates among resident doctors based in Lagos and Edo states, with 25% of all ADRs observed reported. This finding leaves more than a third of all observed ADR cases unreported. Oreagba et al.^[10] discovered low reporting rates among community pharmacists in Lagos state with only 3% reporting ADRs to the National Pharmacovigilance Center (NPC). In light of these findings, there seems to be a paucity of data on ADR reporting among pharmacists practicing in hospitals. How knowledgeable are hospital pharmacists about ADRs and ADR reporting in Lagos state, Nigeria? What has been the general attitude and practice of hospital pharmacists toward ADR reporting in Lagos, Nigeria? These are the answers this research seeks to find. These data would produce new insights into a growing problem with a focus on hospital pharmacists in the Southwestern region of Nigeria, which had not been previously studied.

MATERIALS AND METHODS

RESULTS

Pharmacist’s knowledge of ADR

Assessment of pharmacists’ general knowledge of ADR reporting showed that 95% knew the correct definition of ADRs and 69% knew the correct type of ADRs [Table 2].

Table 2: Assessment of general knowledge toward reporting ADRs.

Knowledge of ADR reporting	Response	Private hospital n (%)	Public hospital n (%)	Total n (%)	P-value
1. ADRs are side effects commonly experienced by a patient using a drug.	Yes	15 (37.5)	21 (35.0)	36 (36.0)	0.799
2. ADRs are unexpected effects of a drug when it is being used at normal doses	Yes	38 (95.0)	57 (95.0)	95 (95.0)	1.000
3. ADRs are restricted to orthodox medicines only.	Yes	1 (2.5)	0 (0.0)	1 (1.0)	0.218
4. ADRs are caused by POMs only	Yes	0 (0.0)	0 (0.0)	0 (0.0)	-
5. ADRs can be caused by error, drug abuse or misuse.	Yes	34 (85.0)	47 (78.3)	81 (81.0)	0.253
6. All ADRs are known during clinical trials.	Yes	0 (0.0)	3 (3.0)	3 (3.0)	0.249
7. All ADRs are dose dependent.	Yes	3 (7.5)	10 (16.7)	13 (13.0)	0.314
8. Only life-threatening reactions to a drug should be reported.	Yes	2 (5.0)	2 (3.3)	4 (4.0)	0.677
9. Reporting and documentation of all ADRs is important.	Yes	40 (100.0)	60 (100.0)	100 (100.0)	-
10. ADRs are a major cause of hospital mortality and morbidity.	Yes	31 (77.5)	45 (75.0)	76 (76.0)	0.932
11. Would you be able to report an ADR if it were to occur in your health-care facility?	Yes	34 (85.0)	53 (88.3)	87 (87.0)	0.607
12. Are you aware of the ADR reporting channel in Lagos state/Nigeria?	Yes	23 (57.5)	38 (63.3)	61 (61.0)	0.811
13. Which of the following are types of ADR’s	Type A, B, C, D, E, F and G	27 (67.5)	42 (70.0)	69 (69.0)	0.404
	Type 1, 2, 3, 4, 5, 6 and 7	1 (2.5)	1 (1.7)	2 (2.0)
	Known, unknown and common, uncommon	2 (5.0)	7 (11.7)	9 (9.0)
	Reversible and irreversible	3 (7.5)	6 (10.0)	9 (9.0)
	Do not know	7 (17.5)	4 (6.7)	11 (11.0)

ADR: Adverse drug reaction, POMs: Prescription only medicines

All the respondents, 100% agreed that reporting and documentation of all ADRs were important and 87% were confident in their ability to report ADRs. In addition, 61% were aware of the correct ADR reporting channels while 75% knew the appropriate regulatory agency to obtain ADR forms from, of which 62% and 38% were public and private hospital pharmacists, respectively. Overall, general knowledge scores were 89%.

Information on the sources of information and regulatory bodies used for ADRs forms are shown in Figures 1 and 2, respectively. There was also no statistically significant difference between knowledge of pharmacists and place of practice (P > 0.05).

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Figure 1:

Sources of information on adverse drug reactions.

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Figure 2:

Regulatory body to obtain adverse drug reaction forms.

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DISCUSSION

The theoretical knowledge of ADRs is necessary as it provides an understanding as to why reporting and documentation of all ADRs is vital in reducing morbidity, mortality, and financial burden on patients. Overall, results from this study revealed that 95% of pharmacists across private and public hospitals were knowledgeable about the definition of ADRs (private to public hospital ratio of 0.97). This finding is similar to a Chinese study,^[16] which reported that 89% of hospital pharmacists were knowledgeable on ADR definitions, and another in Egypt, at 94%.^[17] Given the rigorous training in pharmacy school, pharmacists should be well-versed on definitions and classifications of ADRs. Theoretically, pharmacists should be able to differentiate between a side effect and an ADR, which would aid identification and reporting. However, there seemed to be a decline in knowledge with regard to the types of ADR when compared to the definition, as 69% of respondents correctly chose the Rawlins classification of ADRs, which are type A, B, C, D, E, and F.^[1] This decline from 95% to 69% could have been as a result of a lack of training or refresher courses postgraduation or few encounters of ADR presentations in patients. We also found positive knowledge on ADR reporting as 100% of all pharmacists agreed that all ADRs should be reported and documented, regardless of severity, and 87% were confident in their knowledge on how to use the ADR form. These results are higher than what was observed in a study conducted in Jordan which revealed that 73% of pharmacists saw the importance of reporting all ADRs.^[18] It was observed that 70% of hospital pharmacists in Japan understood the ADR reporting system.^[19] This was similar to what our study found with 61% of respondents knowing the correct ADR reporting channel in Lagos State/Nigeria, which is either through the NAFDAC state offices, the zonal pharmacovigilance centers or directly to the NPC in Abuja.^[5] Overall, the knowledge score was high at 89%, higher than reports from an Ethiopian study (57.1%).^[20] This discrepancy could have been because the latter study involved all healthcare professionals, as opposed to this study which focused only on hospital pharmacists, who are custodians of medications. There was no significant degree of association between the demographics of pharmacists and the prediction of knowledge about ADRs.

In this study, there was an overall positive attitude score of 82% which indicates a greater predisposition to reporting ADRs as soon as it is encountered, and this mirrored the overall attitude scores in Ethiopia (78.9%).^[20] The majority of pharmacists in this study were willing to report ADRs encountered at their hospitals as they saw it as part of their responsibility in providing pharmaceutical care to patients, and strongly agreed that doing this increases the value of pharmacists in the healthcare sector. This finding is consistent with studies in China; where 85% of respondents believed that ADR reporting was the responsibility of pharmacists,^[16] and in Lebanon^[21] and Saudi Arabia,^[22] where 79% and 91% of pharmacists, respectively, saw it as a professional obligation.

Given that all erroneously filled or incomplete ADR forms are not sent to the International Drug Monitoring Center in Uppsala,^[5] the willingness to be trained on the identification and filling of ADR forms is vital as this aids the submission of accurate reports. This goes hand-in-hand with the patient being the main focus in ADR reports and is a positive step in ensuring patient safety and medication efficacy. The willingness to learn is seen in this study where almost a third of all pharmacists, more in public hospitals than private hospitals, strongly agree on trainings and the patients being the main focus while reporting. Similar results were seen by Alshabi et al., where 87% of hospital pharmacists in Saudi Arabia agreed to training,^[22] and another in Jordan, where 84% believed that ADR reporting improved quality care of patients.^[18] However, there were fewer agreements on making ADR reporting mandatory by law in this study as 31% of respondents strongly agreed to mandatory reporting. This is lower compared to reports in Saudi Arabia, where 69% of pharmacists felt the need for mandatory reporting.^[23]

In this study, there seems to be a degree of association between a higher level of education and positive attitude to reporting ADRs, at p value = 0.049.

The result obtained states a point estimate of 3.37 with a 95% confidence interval of 0.99 to 11.49. While the p-value indicates that there might be a statistically significant effect, the confidence interval just barely includes the value of 1. This proximity to 1 in the confidence interval suggests that we cannot be confident that there is a true effect, and the association might not be truly statistically significant. This might have occurred because the confidence interval is wide, suggesting a large degree of uncertainty in the estimate. It might also be due to the small sample size in this study, which leads to less precise estimates. Despite the CI including 1, the lower bound is very close to 1, indicating that almost all of the confidence interval suggests an association. Pharmacists with a higher education level beyond their first degrees were 3 times more likely to have a positive attitude to reporting ADRs than those with B. Pharm and Pharm.D degrees as first degrees only. This attitude could most likely be due to exposure, as graduate professionals, to an in-depth curriculum on specific areas of interests/specialization as opposed to generalized areas in undergraduate studies, which would facilitate the practice of what was learned.

There were low practice scores of 23% across both hospitals as opposed to 62.8% recorded in Jordan.^[18] The majority of pharmacists in this study (87%) had encountered ADRs, consistent with studies in Australia (88.4%)^[24] and Saudi Arabia (86.1%)^[22] but only 21% had reported an ADR in the past three months. This results to a ratio of identifying ADRs to reporting them at 0.24 which differs from the higher ADR reporting to identification ratio of 0.83 in China,^[16] 0.90 in Malaysia,^[25] and 0.94 in Saudi Arabia.^[22] Furthermore, there were close similarities between those who had refresher courses and/or training (35%), and reporting rates (21%) which emphasizes the fact that the majority of pharmacists in this study were first-degree holders as consistent with the Chinese study, which revealed that lower education levels were associated with lower reporting rates.^[16] Nevertheless, this difference could have occurred due to variations in the duration of reported ADRs as this study inquired about reporting rates within three months, while the referenced studies asked within a duration of six months.

Comparing pharmacists from both sectors reported higher knowledge and attitude scores with public hospital pharmacists than private, but higher practice scores with private hospital pharmacists than public. Consistent results were found in a study by Hu et al., which could be due to the fact that pharmacists in the public sector have had more years of experience and would have had more encounters with ADRs, making them more knowledgeable and better predisposed to reporting such.^[16] However, an increased work burden, lack of time, and a smaller pharmacist-to-patient ratio, due to migration from the country in recent years, may have contributed to poor practice. Furthermore, a better work environment, electronic medical records, and less work burden may have given privately owned hospitals an edge over public hospitals. In addition to this, the lower number of private hospital pharmacists in this study may have given the pharmacists in public hospitals a greater advantage with knowledge and attitude scores.

CONCLUSION

Hospital pharmacists in Lagos have a high level of knowledge and positive attitude to ADR reporting but there is low practice, especially in the public sector. The introduction of an ADR reporting app to aid spontaneous reporting by patients, caregivers, pharmacists, and other healthcare personnel might improve reporting rates.